DE2330175A1 - Catalysts for solvent-free polyurethane textile coatings - consist of adducts of lactams with hydroxyl cpds., amines, hydrazines or oximes - Google Patents

Abstract

Catalysts for polyurethane polyaddition reactions, consisting of adducts of (A) lactams of formula: (in which X is OH, R is hydrogen, and m is 0-9, or X is nitrogen, R is an aliphatic, araliphatic or opt. alkyl-substd. pyridine gp. and m is 3) with (B) hydroxyl cpds., amines, hydrazines and/or oximes. Amount of catalysts used is 0.4-5 (0.6-3) wt. % or the reaction partners. The catalyst is used in the polyurethane coating or impregnating of textiles, bonding of non-woven fabrics or production of polyurethane films by reactive processes, using little or no solvent. Catalysts are liquids and easily metered into the reaction mixt. Hydrolysis resistance is not impaired, as by use of metal oxide catalysts they also act as diluents and solvents for obtaining the required viscosity.

Description

Bayer Aktiengesellschaft 2330175

Central area of patents, trademarks and licenses

Sf t- each 509 Leverkusen, Bayerwerk

13. JUHi ®? ₃

Coating and lamination of flat structures with polyurethane

The present invention relates to the use of lactam addition compounds as a reaction accelerator for diisocyanate polyaddition reactions in coating and lamination of flat structures after the reactive process.

Polyurethanes have been in the industry for a long time used for the coating and lamination of textile fabrics. A distinction is made here essentially Two and one component systems. The so-called two-component systems are best known in textile coating from polyurethanes of medium molecular weight (prepolymers), which generally carry terminal hydroxyl groups and after application on the coated sheet of a crosslinking with the second component, a polyisocyanate, be subjected. The prepolymers are made from polyesters or polyethers, optionally low molecular weight Chain extenders and diisocyanates produced. By suitable choice of the NCO / OH ratio of the starting materials the desired chain length of the prepolymer can be set.

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The relatively low molecular weight prepolymers can also be used in poor polyurethane solvents such as ethyl acetate, Butyl acetate and others are dissolved.

If the chain is extended further (NCO / OH = 1), products are created that can only be used in strongly polar solvents such as dimethylformamide, tetrahydrofuran, MEK o.a. or are also soluble in mixtures of these solvents. These polymers already have such a high molecular weight that they do not need any further extension or crosslinking after application, they become final crosslinked systems considered.

In addition to the end-crosslinked systems that work in organic solvents are used, end-crosslinked systems in the form of aqueous suspensions or dispersions are also used manufactured and used for textile coating.

However, all of these coating processes have the disadvantage that after application a considerable amount Solvent or dispersant must be evaporated. In the case of organic solvents, these must be followed the drying process either destroyed or supplied to the atmosphere in diluted form, or they are included in the work process again after careful cleaning.

About the possibility of producing solvent-free polyurethanes, has been used in foam manufacture for a long time. Polyester or polyether are used Mixed di- or polyisocyanates and reacted in the presence of catalysts and water. The reaction produces a considerable amount of carbon dioxide, which is used as a blowing agent.

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In analogy to the production of foam, for the coating and lamination of textiles, reactive systems are also used in which carbon dioxide is split off is omitted. Compact polyurethanes are then formed, used as catalysts for the polyaddition reaction metal oxide catalysts are preferred. Like all catalysts that remain unchanged in the reaction product, accelerate but also metal oxides not only the build-up but also the breakdown reaction of the polyurethanes. These catalysts also have the disadvantage that they are difficult to dose substances. Overdoses can be easy lead to an over-rapid forward reaction, but also an accelerated reverse reaction (hydrolysis).

There was consequently a noticeable interest in catalyst systems find the mixture of polyisocyanates, chain extenders, which can be easily dosed in the solvent-free phase and / or polyethers and / or polyesters can be added. At the same time, the catalysts should also have an optimal acceleration effect.

Over-fast reactions, such as those caused by the addition of amines, are just as unfavorable as very slow reactions, such as when adding lactams, for example. Many lactams also have the disadvantage that e's are solid and therefore more difficult to dose substances.

From DOS 2 117 576 it is known that addition compounds of lactams with alcohols, amines, hydrazines, oximes or water, as described for the first time in DOS 2 062 288, the polyisocyanate addition reaction is very strong accelerate. The reason for this effect is probably that the alcohols serving as chain extenders, Amines etc. in the adducts in "activated", i.e. special

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reactive form. In DOS 2 117,576, the production of the polyurethanes is described both in solvents as well as in bulk, but does not refer to the production of coatings, impregnations or foils referred to after the Reaktiwerfahren. It was as a result the strong acceleration of the reaction through the lactam addition compounds (according to DOS 2 117 576 approx. 300 times the reaction rate) it is not to be expected that such reactive mixtures will have sufficient pot lives for use would have in the areas just mentioned.

Surprisingly, however, it has now been found that with suitable Dosage Addition products of lactams with water, glycols, ethanolamine, diethanolamine etc., as they are according to the Procedure of the German OffenlegungsSchriften 2 062 288 and 2,062,289 are easily accessible as catalysts in the production of foils and for impregnation, Coatings and laminations of textile fabrics according to the low-solvent or particularly preferably solvent-free Reaktiwerfahren are eminently suitable.

The invention thus relates to the use of addition compounds the end

a) Hydroxy compounds and / or amines and / or hydrazines and / or oximes and

b) lactams of the general formula

A. 14 < R - CH ₂ - C.
I. = O ? 76 X
VcH ₂ : I.
N - H Le

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wherein

X stands for a CH group, in which case R is hydrogen and

m represents a number from 0 to 9

or

X stands for a nitrogen atom, in which case R is an aliphatic radical, an araliphatic radical or one optionally by lower alkyl radicals

substituted pyridine radical, and m = t 3

as catalysts in the production of foils or in the impregnation, lamination or coating of textiles Flat structures according to the reaction process.

The preparation according to the invention happens to be used catalysts, as described in DOS 2,062,288 and 2,062,289, by simple mixing of the lactams or azalactams with the particular adduct former at temperatures of 0 to 100 ⁰ C, preferably 30 to 70 ° C. Preference is given to using 0.3-4 mol of the adduct former per mole of the (aza) lactam.

Lactams, in particular, are used as starting compounds for the preparation of the catalysts to be used according to the invention of ω-aminocarboxylic acids into consideration, such as 3-aminopropionic acid, 4-aminobutyric acid, 5-aminovaleric acid, 6-aminocaproic acid, lo-aminocapric acid; N-substituted azalactams such as 1-N-methylhexahydro-1,4-diazepinon- ( 3), 1-N-butyl-hexahydro-1,4-diazepinon- (3), 1-N-Benzyl-hexahydro-1,4-diazepinon- (3), l-N-t * -pyridyl-hexahydro-1,4-diazepinone- (3) etc. Preferred Lactams are butyrolactam, valerolactam, 1-N-methylhexahydro-1,4-diazepinon- (3) and in particular ε, -caprolactam.

The adduct formers are preferably mono-, di- or trifunctional Hydroxy compounds are used, particularly preferred Water, ethylene glycol, Ν, Ν-dimethyl-ethanolamine,

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N-methyl-diethanolamine, trimethylolpropane, glycerin or Mixtures of these compounds.

In order to achieve an optimal acceleration effect, it is necessary to add the lactam addition compounds to the reacting system of polyisocyanates and compounds with OH and / or NH groups in a certain amount. Preferably about 0.4 to 5% by weight, particularly preferably 0.6 to 3% by weight , based on the total of the reactants, are metered in. If the stated proportions are adhered to, the coating compositions can easily be applied safely, ie the reaction takes place quickly, but not too quickly.

The polyaddition reaction generally leads to films or coatings that are absolutely homogeneous, i.e. non-porous are. If, on the other hand, the adduct of lactam and water is chosen as the catalyst, COp is evolved during the reaction, and a foam structure is created. Surprisingly, in this case, the reaction can be controlled so that Products are created that resemble mechanically whipped foams, as they are generally used for foam coating Textiles used. It is also noticeable that these foams have closed and pore-free surfaces, if you create them on a steel belt, for example.

Another advantage of those to be used according to the invention Lactam adducts are liquid compounds that are found in the liquid polyisocyanates, prepolymers, Polyesters and polyethers are easily soluble, which are used for coating or lamination, textile impregnation or Foil production are used. So you have with the dosage, with the mixing and with the application in in each case a system is present which consists of mutually soluble or liquid components. This avoids that for example - as is possible in other systems - solid catalysts agglomerate into dots

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and thus give rise to uneven failure of the coating or lamination. It is also of particular advantage that the lactam adducts represent solvents or swelling agents for polyurethanes and other polymers.

The lactam adducts thus take on a further function in these systems. They act as a diluent and as a solvent for the reactants. The use of lactam adducts in laminating or coating pastes has proven itself thus as particularly advantageous, because with their help you can

1. the polyaddition reaction is catalyzed uniformly,

2. the desired viscosity of the coating or lamination paste can be set and also

3. the reaction time can be adjusted to the operational conditions without overdosing or underdosing being of paramount importance.

In the production of films, coatings, laminations or impregnated textiles according to the invention are made from diisocyanates and higher molecular weight polyhydroxy compounds in a known manner. It is possible the reactants in the presence of the lactam adducts in one implement one-shot process. In many. In some cases, however, it is more advantageous to start with the higher molecular weight polyhydroxyl compounds and a portion of the diisocyanate to prepare a prepolymer with terminal hydroxyl groups, which then according to the invention with the lactam addition compounds and the remaining diisocyanate to form a high molecular weight polyurethane is networked. In this way, in particular, the strength, toughness, notch toughness and structural strength affect the end products favorably.

Overall, with an approximately equivalent ratio between diisocyanates and compounds with reactive Hydrogen atoms worked.

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When drawing up the recipe, the self-consumption of isocyanate is included to be taken into account by the added adduct.

As starting components to be used according to the invention, aliphatic, cycloaliphatic, araliphatic _f aromatic and heterocyclic polyisocyanates come into consideration, as they are, for. B. by W. Siefgen in Justus Liebigs Annalen der Chemie, 562, pages 75 to 136, are described, for example ethylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 1,12-dodecane diisocyanate, cyclobutane 1,3-diisocyanate, cyclohexane-1,3- and 1,4-diisocyanate and any mixtures of these isomers, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl-cyclohexane (DAS 1 202 785), 2 , 4- and 2,6-hexahydrotoluylene diisocyanate and any mixtures of these isomers, hexahydro-1,3- and / or -A , 4-phenylene diisocyanate, perhydro-2,4'- and / or -4,4'-diphenylmethane -diisocyanate, 1,3- and 1,4-phenylene diisocyanate, 2,4- and 2, G-tolylene diisocyanate and any mixtures of these isomers, diphenylmethane-2,4'- and / or -4 _f 4'-diisocyanate, naphthylene- 1,5-diisocyanate, triphenylmethane-4,4 ', 4 "-triisocyanate, polyphenyl-polymethylene-polyisocyanates, as obtained by aniline-formaldehyde condensation and subsequent phosgenation and, for example, in British patents 874 430 and 848,671, perchlorinated aryl polyisocyanates as described, for example, in German Auslegeschrift 1,157, carbodiimide-containing polyisocyanates as described in German patent 1,092,007, and diisocyanates as described in American patent 3,492,330 , Polyisocyanates containing allophanate groups, as described, for example, in British patent specification 994 890, Belgian patent specification 761 626 and published Dutch patent application 7 102 524, polyisocyanates containing isocyanurate groups, as described, for example, in German patents 1,022,789, 1,222,067 and 1 027 394 and in the German Offenlegungsschriften 1 929 034 and 2 004 048

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polyisocyanates containing urethane groups, as described, for example, in Belgian patent specification 752 261 or in American patent specification 3,394,164, polyisocyanates containing acylated urea groups according to German patent specification 1 230 778, polyisocyanates containing biuret groups, as described, for example, in German patent specification 1 101 394, in British patent specification 889 050 and in French patent specification 7 017 514, polyisocyanates produced by telomerization reactions, as described, for example, in Belgian patent specification 723 640, polyisocyanates containing ester groups, as described, for example, in British patents 965 474 and 1,072,956, in the American patent 3,567,763 and in the German patent 1,231,688, reaction products of the above-mentioned isocyanates with acetals according to the German patent 1,072,385.

It is also possible to use the technical isocyanate production distillation residues containing isocyanate groups, optionally dissolved in one or more of the aforementioned polyisocyanates, to be used. Furthermore it is possible to use any mixtures of the aforementioned polyisocyanates.

The technically easily accessible polyisocyanates, for example 2,4- and 2,6-tolylene diisocyanate and any mixtures of these isomers ("TDI"), polyphenyl-polymethylene polyisocyanates, such as those produced by aniline-formaldehyde condensation and are particularly preferred subsequent phosgenation are produced ("crude MDI") and carbodiimide groups, urethane groups, allophanate groups, isocyanurate groups, urea groups of the polyisocyanates containing biuret groups ("modified polyisocyanates ·»).

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Starting components to be used according to the invention are also Compounds with at least two isocyanate-reactive hydrogen atoms and a molecular weight usually from 400 to 10,000. This is understood to mean, in particular, compounds containing two or three hydroxyl groups, especially those with a molecular weight of 800 to 6000, preferably 1000 to 4000, e.g. containing hydroxyl groups Polyesters, polyethers, polythioethers, polyacetals, polycarbonates or polyester amides, as are known per se for the production of homogeneous and cellular polyurethanes.

The possible polyesters containing hydroxyl groups are, for example, reaction products of polyhydric, preferably dihydric and optionally additionally trihydric alcohols with polybasic, preferably dibasic, carboxylic acids. Instead of the free polycarboxylic acids, it is also possible to use the corresponding polycarboxylic acid anhydrides or corresponding polycarboxylic acid esters of lower alcohols or mixtures thereof to produce the polyesters. The polycarboxylic acids can be aliphatic, cycloaliphatic, aromatic and / or heterocyclic in nature and optionally substituted and / or unsaturated, for example by halogen atoms. Examples include: succinic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, phthalic acid, isophthalic acid, trimellitic acid, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, tetrachlorophthalic anhydride, a mixture of tetrachlorophthalic anhydride, a mixture of diminic acid, maleic anhydride, a mixture of diminic, maleic anhydride, and oleic, maleic anhydride, and oleic, maleic anhydride, and oleic acid, maleic anhydride, and oleic acid, maleic anhydride, and oleic anhydride with monomeric fatty acids, terephthalic acid dimethyl ester and

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Terephthalic acid bis-glycol ester. As polyhydric alcohols e.g. ethylene glycol, propylene glycol (1,2) and - (1,3), Butylene glycol (1,4) and - (2,3), hexanediol (1,6), octanediol (1,8), neopentyl glycol, cyclohexanedimethanol (1,4-bis-hydroxyaethylcyclohexane), 2-methyl-1,3-propanediol, Glycerine, trimethylolpropane, hex.antriol- (1,2,6), butanetriol- (1,2,4), Trimethylolethane, also diethylene glycol, Triethylene glycol, tetraethylene glycol, polyethylene glycol ^ Dipropylene glycol, polypropylene glycols, dibutylene glycol and Polybutylene glycols in question. The polyesters can be proportionate have terminal carboxyl groups. Also polyesters from lactones, e.g. fc-caprolactone or hydroxycarboxylic acids, e.g. <y-hydroxycaproic acid can be used.

The polyethers which can be used according to the invention, preferably containing two to three hydroxyl groups, are those of the type known per se and are, for example, by polymerizing epoxides such as ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, styrene oxide or epichlorohydrin with themselves, for example in the presence of BF, . or by adding these epoxides, optionally mixed or sequentially, to starting components with reactive hydrogen atoms such as alcohols or amines, for example water, ethylene glycol, propylene glycol- (1,3) or - (1,2), trimethylolpropane, 4,4'-dihydroxydiphenylpropane , Aniline, ammonia, ethanolamine or ethylenediamine. In many cases, those polyethers are preferred which predominantly (up to 90% by weight, based on all OH groups present in the polyether) have primary OH groups. By Viny! Polyethers modified polymers, such as are formed by the polymerization of styrene or acrylonitrile in the presence of polyethers (US Patents 3,383,351, 3,304,273, 3,532, "093, 3110695, German Patent Specification l 152 536 _t), are suitable for , also polybutadienes containing OH groups "

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^ 233ΓΠ75

Among the polythioethers are in particular the condensation products of thiodiglycol with themselves and / or with others Glycols, dicarboxylic acids, formaldehyde, aminocarboxylic acids or amino alcohols are listed. Depending on the Cο componentη acts the products are polythio mixed ethers, polythio ether esters or polythioether ester amides.

Suitable polyacetals are, for example, the compounds which can be prepared from glycols such as diethylene glycol, triethylene glycol, 4,4'-dioxethoxy-diphenyldimethyl methane, hexanediol and formaldehyde . Polyacetals suitable according to the invention can also be prepared by polymerizing cyclic acetals.

Polycarbonates containing hydroxyl groups are those of the type known per se, which are produced, for example, by reacting diols such as propanediol (1 , 3), butanediol (1,4) and / or hexanediol (1,6), diethylene glycol, Triethylene glycol or tetraethylene glycol with diaryl carbonates, such as diphenyl carbonate or phosgene, can be produced.

The polyester amides and polyamides include, for example, those made from polyvalent saturated and unsaturated carboxylic acids or their Anhydrides and polyvalent saturated and unsaturated amino alcohols, diamines, polyamines and their mixtures, Mostly linear condensates.

Representatives of this to be used according to the invention Compounds are, for example, in High Polymers, Vol. XVI, "Polyurethanes, Chemistry and Technology", written by Saunders-Frisch, Interscience Publishers, New York, London, Volume I, 1962, pages 32 - 42 and pages 44 - 54 and Volume II, 1964, Pages 5-6 and 198 - 199, as well as in the plastics manual, Volume VII, Vieweg-Höchtlen, Carl-Hanser-Verlag, Munich, 1966, e.g. on pages 45 to 71.

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It is easily possible to differentiate the reacting systems To add surcharges. These primarily include fillers and coloring substances, e.g. color pigments organic or inorganic in nature. It is also possible to include dyes in the polyaddition reaction, provided they have one or more reactive groups, for example hydroxyl or amino groups. As examples Malachite green and other basic dyes are mentioned. As it turned out, these dyes are present in the systems but only about a poor lightfastness. The inadequate lightfastness is dye-specific and not process-related, as evidenced by using other suitable dyes.

According to the invention, using those known per se Techniques porous or homogeneous foils, coatings or laminations are produced, either after the direct coating or by the reverse procedure. The catalysts to be used according to the invention are also eminently suitable to accelerate the bonding of nonwovens with reactive polyurethane systems. Preferably it is used at all The described process with little solvent, particularly preferably solvent-free, worked.

The recipes used in the examples are summarized below:

Recipe 1:

100 g of a slightly branched polyester made from adipic acid,

Diethylene glycol and trimethylolpropane (OH number 56) 20 g crude MDI (technical mixture of polyphenyl-polymethylene polyisocyanates)

2 g addition compound from E -caprolactam and water (Molar ratio 1: 1.2).

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Recipe 2:

100 g of the polyester from formulation 1 20 g of raw MDI

2 g addition compound from £. -Caprolactam and ethylene glycol (Molar ratio 1: 1).

Recipe 3 '·

100 g of the polyester from formulation 1 40 g of raw MDI
1 g adduct of ε-caprolactam and water (molar ratio 1: 1.2)

Recipe 4:

100 g of a prepolymer with terminal hydroxyl groups, 20 g of diphenylmethane diisocyanate

1 g adduct of ε-caprolactam and N, N-dimethylethanolamine (molar ratio 1: 1).

To produce the prepolymer, 100 parts of the polyester from recipe 1 are mixed with 8 parts of the reaction product 1 mole of trimethylolpropane and 3 moles of tolylene diisocyanate (technical isomer mixture) reacted.

Recipe 51

50 g of the polyester from formulation 1, 50 g of a linear polyester from adipic acid and diethylene

glycol (OH number 40), 50 g raw MDI
3 g adduct of fc-caprolactam and water (molar ratio 1: 1.2)

Recipe 6:

100 g of the polyester from formulation 1 25 g of raw MDI

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0.05 g yellow dye (bis- / 5- (dimethylamino) -phenyl7-methylenimine hydrochloride)

1 g adduct of ε-caprolactam and ethylene glycol (molar ratio 1: 1).

Example I.

The constituents of recipe 1 are intimately mixed with a high-speed stirrer and spread out with a doctor blade to form a 0.3 mm thick film. The reaction at room temperature and 60 % relative humidity and also the reaction in the drying cabinet at 70 ^° C. result in transparent films which are evenly interspersed with small vesicles which are barely recognizable to the naked eye.

In a second experiment, 10 g of the isocyanate are first reacted with the dehydrated polyester of formulation 1 for 10 minutes at 110 ^° C. to form a prepolymer with terminal hydroxyl groups and this prepolymer is processed further with the remaining isocyanate and the catalyst as above. The result is a film with improved strength and notch toughness.

Example II

The mixture of Example I is applied to a polyurethane-coated substrate using a film printing stencil, which beforehand with an additional spread of the caprolactam-water adduct had been provided. After the reaction is the polyurethane coating provided with a raised print pattern, the contours of which are sharp. The print contains a foam structure, which is superficially provided with a skin. The adhesion to the polyurethane substrate is very good.

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Example III

Mixtures of formulations I and II are colored with different colored pigments. Color pastes that are accordingly The two recipes were prepared, are applied in the form of a pattern on a substrate. After graduation The reaction has created a pattern on the substrate in which defined raised and flat contours alternate.

Example IV

The components of formulation 3 are intimately mixed under a high-speed stirrer, with a doctor blade on a separating support (Paper, steel tape, fabric) applied and reacted at room temperature. On the rising mass there is a Unconsolidated needle felt made of polyamide staple fibers is applied and slightly depressed.

The result is a material that consists of an unconsolidated fleece on one side and one on the other has pore-pierced skin. In the middle there is a border zone into which the reaction produced Foam has penetrated and a fiber-free foam layer. The bond in the composite is so good that a mechanical one is attempted Separation at any layer of the composite leads to the mechanical destruction of one or more layers.

Example V

A foam produced according to recipe 3 is pressed in statu nascendi into a needled fleece, which consists of a mixture of polyester and polyamide fibers. After the R _e action the fleece with the resulting polyurethane foam to form an elastic porous dressing is connected. The tear and tear strength of the composite is excellent.

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Example VI

The ingredients of recipe 4 are mixed under a high-speed stirrer and placed on a prepared steel belt with a Squeegee applied. On the mass, which begins to react immediately after mixing, a cotton rough weave becomes laminated with the pile side. The result is an abrasion-resistant, pliable polyurethane synthetic leather.

Example VII

The components of recipe 5 are intimately mixed under the high-speed stirrer and applied directly to the Back of a flooring material painted and calibrated. After the reaction has ended, the floor covering has a backing defined thickness, which consists of a foam structure inside and a skin-like surface composed.

Example VIII

The components of recipe 6 are intimately mixed and smeared onto a release liner with a squeegee. After the reaction has ended, an intensely yellow colored, homogeneous one can be seen and lift off the transparent polyurethane film from the separating support.

Example IX

50 g of a paste according to recipe 2 are applied with a doctor blade on a prepared steel strip as a separating carrier accommodated in a heating tunnel at 70 ⁰ C for reaction. After leaving the channel and cooling down, 75 g of a mixture according to recipe 5 are applied with a doctor blade. A roughened cotton fabric is placed on the wet layer with the non-roughened side. The reaction is carried out at a temperature of 70 ° C. The result is a foam with a density of around 300, which acts as a lamination binder between the primarily formed film and the textile. Le A14 976 . - 17 -

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The result is a flexible composite material that can be separated from the steel strip without any effort.

If example IX is repeated using a prepolymer corresponding to the second experiment of example I, then a composite material with increased notch toughness is obtained.

Claims (1)

Claims 1. Use of addition compounds from a) lactams of the general formula CH ₀ - C = 0 RX NH wherein X represents an OH group, in which case R represents hydrogen and ■ represents a number from 0 to 9 or X stands for a nitrogen atom, in which case R is an aliphatic radical, an araliphatic radical or a pyridine radical optionally substituted by lower alkyl radicals and • m stands for the number 3 and
Le A 14 976 - 18 - 509812/1049 b) Hydroxy compounds and / or amines and / or hydrazines and / or oximes as catalysts in the coating, lamination or impregnation of textiles with polyurethanes, the bonding of nonwovens with polyurethanes or the production of polyurethane foils according to the reaction process, the addition compounds in an amount of 0.4 to 5% by weight, based be used on the sum of the reactants. Le A 14 976 - 19 - 509812/1049